Important: This documentation covers modern versions of Yarn.
For 1.x docs, see
yarn addyarn binyarn cache cleanyarn config getyarn config setyarn config unsetyarn configyarn constraints queryyarn constraints sourceyarn constraintsyarn dedupeyarn dlxyarn execyarn explain peer-requirementsyarn explainyarn infoyarn inityarn installyarn linkyarn nodeyarn npm audityarn npm infoyarn npm loginyarn npm logoutyarn npm publishyarn npm tag addyarn npm tag listyarn npm tag removeyarn npm whoamiyarn packyarn patch-commityarn patchyarn plugin import from sourcesyarn plugin importyarn plugin listyarn plugin removeyarn plugin runtimeyarn rebuildyarn removeyarn runyarn searchyarn set resolutionyarn set version from sourcesyarn set versionyarn stageyarn unlinkyarn unplugyarn upyarn upgrade-interactiveyarn version applyyarn version checkyarn versionyarn whyyarn workspaceyarn workspaces focusyarn workspaces foreachyarn workspaces list

yarn why

Display the reason why a package is needed.


$> yarn why <package>


Explain why lodash is used in your project :

yarn why lodash




List, for each workspace, what are all the paths that lead to the dependency


Format the output as an NDJSON stream


Also print the peer dependencies that match the specified name


This command prints the exact reasons why a package appears in the dependency tree.

If -R,--recursive is set, the listing will go in depth and will list, for each workspaces, what are all the paths that lead to the dependency. Note that the display is somewhat optimized in that it will not print the package listing twice for a single package, so if you see a leaf named "Foo" when looking for "Bar", it means that "Foo" already got printed higher in the tree.